Aspects of gene expression in B cell lymphomas

Gene expression profiling has been used extensively for the analysis of human lymphomas. Besides the analysis of whole tissue or blood samples, genechip studies have also been applied to lymphoma cells isolated by cell sorting from cell suspensions or by laser microdissection from tissue sections. Such studies were successfully applied to clarify the cellular origin of lymphomas by comparison to normal B cell subsets, to gain insights into pathogenetic mechanisms, to develop molecular classifiers for differential diagnosis, to identify so far unrecognized subgroups among current lymphoma entities, and to establish predictors of prognosis. In our own work, we initially studied gene expression of Hodgkin lymphoma cell lines and revealed, for example, a global downregulation of the B cell gene expression programme and an aberrant expression of multiple receptor tyrosine kinases in these cells. We are now studying gene expression profiles from microdissected tumour cells of Hodgkin lymphoma.